Plans to send Rohingya refugees back to Myanmar on Thursday have gathered momentum, with reports of Bangladesh armed forces gathering in the Cox’s Bazar camps and allegations that refugees have been assaulted by the authorities for refusing to cooperate.

The army, police and paramilitary troops have moved into several of the camps, where over 700,000 Rohingya are living after fleeing a campaign of violence, described as genocide by a UN fact-finding mission, carried out by the Myanmar military in August 2017.

Noor Qadar, a 29-year-old Rohingya refugee in Jamtoli camp, said many families, even those not among the list approved for return by Myanmar, had gone into hiding.

“The army is in every corner of the Jamtoli and Hakimpara camps, sitting and checking people and not letting them move between camps,” said Qadar. “People are too afraid to leave their houses or eat. Some left our block at midnight using secret paths for other camps, especially Kutupalong, where there is not so much fear about repatriation.”

Jani, 30, a Rohingya living in camp 14, said the security presence had doubled in the past two days in several settlements, elevating the panic among the Rohingya. “When the sun sets the security teams come to every entry point in the camps and they don’t leave till the morning,” he said. “People are running away and spending days and nights in the forest or other camps.”

There have also been reports of Bangladesh camp officials, known as CICs, assaulting Rohingya who have refused to cooperate. In a video, verified by the Guardian, Ata Ullah, a Rohingya leader in Chakmarkul Camp 21 alleges that he was beaten in the office of a CIC officer “with a large stick” on Monday after he was unable to provide them with list of Rohingya in his camp. “They stepped on my neck, I could not stand it,” Ullah said in the footage. “You can see from my face how I was beaten.”

It is the latest signal that the repatriations, due to begin on Thursday, may not be voluntary, despite multiple assurances by the Bangladesh foreign secretary and the refugee commissioner that they would not force any Rohingya to go back against their will.

I’ve heard they will force us cross the border. We slipped out of the camp because I could not take the risk

Dozens of Rohingya families interviewed by the Guardian, who were placed on a list of 2,200 refugees “approved” for return by Myanmar without their consent, said they did not want to return under the current conditions. Many had fled the camps and gone into hiding, while for others the prospect of going back was so alarming they had attempted suicide.

Nurul Islam, a Rohingya community leader in Unchiprang refugee camp, Cox’s Bazar, said that up to 50 families in the vicinity hadgone into hiding.

“Last week the officials told several families sternly that they would no more be allowed to stay in Bangladesh and have to return to Myanmar and almost all of them have disappeared from their shacks in our camp in the past three or four days,” Islam told the Guardian. “Like all other Rohingya they are too scared to return to Burma. So, they have gone into hiding.”

Forced repatriation also risks splitting up families. Osiullah, who like many other Rohingya uses one name, said he had gone into hiding after discovering that three of his children, the youngest aged five, were on the list for return while he, his wife and three other children were not.

“I got terribly scared to find the names of only three of children listed,” he said. “I’ve heard they will force us cross the border. We slipped out of the camp because I could not take the risk.”

The UN has repeatedly called for a halt to the repatriation plans. UNHCR said it would not be facilitating or providing assistance for return, other than interviewing Rohingya on the list and assessing their willingness to go back. On Tuesday Michelle Bachelet, the UN high commissioner for human rights, condemned the “terror and panic” it was causing Rohingya who were at “imminent risk of being returned to Myanmar against their will.”

There has been no statement on the issue from Myanmar’s state counsellor, Aung San Suu Kyi, who has been at the Asean summit in Singapore this week. There is little sign she is receiving international pressure over the repatriation plans. Speaking at a press conference at the summit on Tuesday, the US national security adviser John Bolton said both he and Vice President Mike Pence, who is leading the US summit delegation, had “nothing new” to say about the Rohingya. However, on Wednesday morning it was confirmed that Pence would be meeting Aung San Suu Kyi later on Wednesday.

But Malaysian prime minister Mahathir Mohamad, who was also at the summit, was vocal in his condemnation of Aung San Suu Kyi. “It would seem that Aung San Suu Kyi is trying to defend what is indefensible,” said Mahathir, speaking before he made a speech at the summit. “They are actually oppressing these people to the point of killing them, mass killing.”